线状要素的动态分段与制图综合

线状要素通常以弧段-结点模型表示和存储在地理信息系统中,不能完整有效地描述真实世界.动态分段则不同,它将线状要素作为一个整体进行描述,以事件表描述各种现象沿着线状要素的动态变化,是一种更复杂、更灵活的数据模型.以动态分段模型为基础,针对河流和道路网络,提出了将弧段形式的线状要素组织为路径系统的方法,并分析各个完整线状实体在网络结构中的相对重要性.以完整线状实体为单元,着眼于网络结构进行制图综合,从而更好地保持网络的总体结构.最后对上述方法进行了简单的试验分析.

Line Generalization Based on Dynamic Segmentation

Lines are represented by arc_node model in most geographical information systems. Arc_node model divide lines into segments and cannot manipulate lines as a whole. In contrast, dynamic segmentation model groups arcs into routes, thus routes can represent intact lines. Based on dynamic segmentation model, this paper proposes a method to organize arcs into route systems and analyze their relative importance related to the linear network. The cases of river system and road network are discussed. Structural parameters are further derived for each route for network generalization. Based on these parameters, linear entities are selected as a whole in a structured way, so that the overall structure of linear network may be maintained. A case study is also carried out to test the method using sample road data in Guangdong Province.